New Delhi, Sept. 9 -- Apple Inc. kicked off its annual launch event on Wednesday at its Cupertino, California, headquarters, where it is widely expected to unveil a pricey folding smartphone called iPhone Duo.

The event, the first with new CEO John Ternus at the helm, will be the most noticeable overhaul of Apple's flagship product since it removed the physical home button from the iPhone X in 2017. The iPhone brought in $209.6 billion, or just over half of Apple's sales, in its most recent fiscal year.

Ternus previously served as Apple's hardware chief but has kept a low profile aside from a handful of product introductions and sustainability initiatives. It will fall to Ternus to persuade Apple's customers that they need a foldable de...